ELECTRICAL STEEL SHEET WITH ADHESIVE SURFACE COATING, LAMINATED CORE AND METHOD OF ITS MANUFACTURING

Claims

1. A sheet of electrical steel with an adhesive surface coating containing electrical steel sheet; an adhesive coating that is provided on at least a portion of one surface or both surfaces of an electrical steel sheet, wherein the adhesive coating includes a cross-linkable thermoplastic resin A and a thermoplastic resin B different from the cross-linkable thermoplastic resin A, wherein in the adhesive coating, the peak temperature on the logarithmic decrement curve measured by testing with a physical pendulum is 130-150°C, and the ratio P1 / P2 of the peaks for the peak logarithmic decrement P1 on the logarithmic decrement curve after heating at 200°C for 1 min to the peak logarithmic decrement P2 on the logarithmic decrement curve before heating is 0.70-1.

30.

2. A sheet of electrical steel with an adhesive surface coating according to paragraph 1, in which P2 is 0.07-0.

30.

3. A sheet of electrical steel with an adhesive surface coating according to claim 1, in which the adhesive coating has a pencil hardness of 3H-4H before heating.

4. A sheet of electrical steel with an adhesive surface coating according to paragraph 1, in which P1 is 0.05-0.

25.

5. A sheet of electrical steel with an adhesive surface coating according to claim 1, in which the adhesive coating after heating has a hardness according to the pencil scale of 5H-6H.

6. An electrical steel sheet with an adhesive surface coating according to claim 1, wherein the cross-linkable thermoplastic resin A is one or more resins selected from the group consisting of a (meth)-acrylic resin and a polyester resin.

7. A laminated core comprising a plurality of sheets of electrical steel with an adhesive surface coating according to any one of claims 1-6, wherein the sheets of electrical steel with an adhesive surface coating are laid in a stack, wherein the sheets of electrical steel are glued together by means of a cured coating of the adhesive coating.

8. The laminated core according to item 7, wherein: the laminated core has a filling factor of 96-98%.

9. A method for manufacturing a sheet of electrical steel with an adhesive surface coating, comprising a coating step of applying a coating liquid to at least a portion of one surface or both surfaces of the electrical steel sheet to form an adhesive coating to obtain a coated steel sheet; and a step of forming an adhesive coating, in which the coated steel sheet is heated to a drying temperature of 100-200°C at a temperature increase rate of 6.0°C / s or less, the coated steel sheet is maintained within a temperature range of -10°C relative to the drying temperature to the drying temperature for 10-90 s, and the coated steel sheet is dried to form an adhesive coating on the surface of the electrical steel sheet.

10. A method for producing an electrical steel sheet with an adhesive surface coating according to claim 9, wherein, at the coating application step, the coating liquid for forming the adhesive coating contains a cross-linkable thermoplastic resin A and a thermoplastic resin B different from the cross-linkable thermoplastic resin A, and the weight ratio of the cross-linkable thermoplastic resin A to the thermoplastic resin B is 97 / 3-70 / 30.

11. A method for manufacturing a laminated core containing a coating step of applying a coating liquid to at least a portion of one surface or both surfaces of the electrical steel sheet to form an adhesive coating to obtain a coated steel sheet; a step of forming an adhesive coating, in which a coated steel sheet is heated to a drying temperature of 100-200°C at a temperature increase rate of 6.0°C / s or less, the coated steel sheet is maintained within a temperature range from -10°C relative to the drying temperature to the drying temperature for 10-90 s, the coated steel sheet is dried and an adhesive coating is formed on the surface of the electrical steel sheet to obtain an electrical steel sheet with an adhesive surface coating; a cutting stage in which a sheet of electrical steel with an adhesive surface coating is cut to obtain a cut element; a stacking stage in which a plurality of cut out elements are stacked to form a layered body; a gluing stage in which the layered body is heated to a compression temperature within a temperature range of 200-300°C and the layered body is maintained within a range of -10°C relative to the compression temperature to the compression temperature for 1-60 min with a compression force of 0.5-10 MPa applied.